Super Gussun Oyoyo is a game that can best be described as a mixture of Tetris and Lemmings. There are two prototypes of this game, one of which was provided by Dizrythmia, the other previously released.

Super Gussun Oyoyo is a fun, if challenging, puzzle game. It basically combines the block fitting of Tetris with the impending suicide of your character like in Lemmings. Dizrythmia picked up this prototype off Yahoo Japan auctions a while back (it was on sale July 2008, I archived that here). The prototype cart is pretty typical for Banpresto prototypes, with a black and white label with the game logo on it.

Prototype - front

Prototype - back

Dizrythmia was kind enough to dump his prototype and provide it to me for release. Here are some of the differences I noticed:

no "sample" in the title screen

music in the demo demonstration stage

inclusion of a demo of the first stage

sound effect every time the water level goes up

points number comes up if you put a block right next to the dude

extra men follow you around, rather than simply get collected.

icon beside number of lives is different

high scores for each level are different (far smaller in the final version)

As far as I could tell, there are no differences in the text of the game.

Prototype

Final

Prototype - extra men are simply picked up

Final extra men follow you around and are added when you pass the level.

In addition to Dizrythmia's prototype, there is another ROM image of Super Gussun Oyoyo that is floating around that is marked as a sample. Though certainly it is not identical to the final version of the game bitwise, any differences within actual gameplay, graphics and sound are too subtle for me to find. Looking at a tile viewer, it is pretty clear that most of the differences between the binaries are in the blank areas of the ROM image (these appear as "checker-board" patterns in a tile viewer, with varying amounts of garbage).